266 research outputs found

    Finite element modeling of electromagnetic fields and waves using NASTRAN

    Get PDF
    The various formulations of Maxwell's equations are reviewed with emphasis on those formulations which most readily form analogies with Navier's equations. Analogies involving scalar and vector potentials and electric and magnetic field components are presented. Formulations allowing for media with dielectric and conducting properties are emphasized. It is demonstrated that many problems in electromagnetism can be solved using the NASTRAN finite element code. Several fundamental problems involving time harmonic solutions of Maxwell's equations with known analytic solutions are solved using NASTRAN to demonstrate convergence and mesh requirements. Mesh requirements are studied as a function of frequency, conductivity, and dielectric properties. Applications in both low frequency and high frequency are highlighted. The low frequency problems demonstrate the ability to solve problems involving media inhomogeneity and unbounded domains. The high frequency applications demonstrate the ability to handle problems with large boundary to wavelength ratios

    Controlled oxygen vacancy induced p-type conductivity in HfO{2-x} thin films

    Full text link
    We have synthesized highly oxygen deficient HfO2x_{2-x} thin films by controlled oxygen engineering using reactive molecular beam epitaxy. Above a threshold value of oxygen vacancies, p-type conductivity sets in with up to 6 times 10^{21} charge carriers per cm3. At the same time, the band-gap is reduced continuously by more than 1 eV. We suggest an oxygen vacancy induced p-type defect band as origin of the observed behavior.Comment: 4 pages, 3 figure

    Rotigotine in Hemodialysis-Associated Restless Legs Syndrome : A Randomized Controlled Trial

    Get PDF
    Background: Restless legs syndrome (RLS) has been associated with insomnia, decreased quality of life, and increased morbidity and mortality in end-stage renal disease. This randomized controlled trial investigated effects of rotigotine in patients with RLS and end-stage renal disease. Study Design: Double-blind placebo-controlled study. Setting & Participants: Adults with moderate to severe RLS (International RLS Study Group Rating Scale [IRLS] >= 15) and Periodic Limb Movement Index (PLMI) >= 15 who were receiving thrice-weekly hemodialysis enrolled from sites in the United States and Europe. Intervention: Following randomization and titration ( Outcomes & Measurements: Primary efficacy outcome: reduction in PLMI, assessed by ratio of PLMI at end of maintenance to baseline. Secondary/other outcomes (P values exploratory) included mean changes from baseline in PLMI, IRLS, and Clinical Global Impression item 1 (CGI-1 [severity of illness]) score. Results: 30 patients were randomly assigned (rotigotine, 20; placebo, 10); 25 (15; 10) completed the study with evaluable data. Mean (SD) PLMI ratio (end of maintenance to baseline) was 0.7 +/- 0.4 for rotigotine and 1.3 +/- 0.7 for placebo (analysis of covariance treatment ratio, 0.44; 95% CI, 0.22 to 0.88; P = 0.02). Numerical improvements were observed with rotigotine versus placebo in IRLS and CGI-1 (least squares mean treatment differences of -6.08 [95% CI, -12.18 to 0.02; P = 0.05] and -0.81 [95% CI, -1.94 to 0.33; P = 0.2]). 10 of 15 rotigotine and 2 of 10 placebo patients were CGI-1 responders (>= 50% improvement). Hemodialysis did not affect unconjugated rotigotine concentrations. The most common adverse events (>= 2 patients) were nausea (rotigotine, 4 [20%]; placebo, 0); vomiting (3 [15%]; 0); diarrhea (1 [5%]; 2 [20%]); headache (2 [10%]; 0); dyspnea (2 [10%]; 0); and hypertension (2 [10%]; 0). Limitations: Small sample size and short duration. Conclusions: Rotigotine improved periodic limb movements and RLS symptoms in the short term among ESRD patients requiring hemodialysis in a small-scale study. No dose adjustments are necessary for hemodialysis patients. (C) 2016 by the National Kidney Foundation, Inc.Peer reviewe

    Change management: The case of the elite sport performance team

    Get PDF
    The effective and efficient implementation of change is often required for both successful performance and management survival across a host of contemporary domains. However, although of major theoretical and practical significance, research to date has overlooked the application of change management (hereafter CM) knowledge to the elite sport performance team environment. Considering that the success of ‘off-field’ sports businesses are largely dependent on the performances of their ‘on-field’ team, this article explores the application of current CM theorizing to this specific setting and the challenges facing its utility. Accordingly, we identify the need and importance of developing theory specific to this area, with practical application in both sport and business, through examination of current knowledge and identification of the domain's unique, dynamic and contested properties. Markers of successful change are then suggested to guide initial enquiry before the article concludes with proposed lines of research which may act to provide a valid and comprehensive theoretical account of CM to optimize the research and practice of those working in the field

    Spectroscopic Survey of the Galaxy with Gaia II. The expected science yield from the Radial Velocity Spectrometer

    Get PDF
    The Gaia mission is designed as a Galaxy explorer, and will measure simultaneously, in a survey mode, the five or six phase space parameters of all stars brighter than 20th magnitude, as well as providing a description of their astrophysical characteristics. These measurements are obtained by combining an astrometric instrument with micro-arcsecond capabilities, a photometric system giving the magnitudes and colours in 15 bands and a medium resolution spectrograph named the Radial Velocity Spectrometer (RVS). The latter instrument will produce spectra in the 848 to 874 nm wavelength range, with a resolving power R = 11 500, from which radial velocities, rotational velocities, atmospheric parameters and abundances can be derived. A companion paper (Katz et al. 2004) presents the characteristics of the RVS and its performance. This paper details the outstanding scientific impact of this important part of the Gaia satellite on some key open questions in present day astrophysics. The unbiased and simultaneous acquisition of multi-epoch radial velocities and individual abundances of key elements in parallel with the astrometric parameters is essential for the determination of the dynamical state and formation history of our Galaxy. Moreover, for stars brighter than V=15, the resolving power of the RVS will give information about most of the effects which influence the position of a star in the Hertzsprung-Russell diagram, placing unprecedented constraints on the age, internal structure and evolution of stars of all types. Finally, the RVS multi-epoch observations are ideally suited to the identification, classification and characterisation of the many types of double, multiple and variable stars.Comment: 33 pages, 11 figures, in press at MNRAS. Figs 1, 3 and 9 included at reduced resolution; available in full resolution at http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1365-2966.2005.09012.

    The Physics of the B Factories

    Get PDF
    This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C
    corecore